Marathon GPM 34mm & 36mm (Officer’s) Watch Review - Hardy in Form and Function
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What’s small, plastic, contracted by the US Department of Defence, and contains radioactive material used in Thermonuclear Weaponry? It’s not a prop in the next James Bond movie, though perhaps it should be. It is in fact this $450 watch from Marathon Watches - the 34mm General Purpose Mechanical (GPM) and its slightly larger brother; the 36mm GPM-SS (Stainless Steel). These basic, rough, and ready timepieces almost look like prototypes but are actually long-established production models that have been tried and tested to the extreme – more on that later.
I spend a lot of time researching watches – either in preparation for a new review or for another pre-owned ‘bargain’. Naturally, a manufacturer’s website is a good place to start gathering dimensions, facts and figures about the timepiece in question. Commonly though, I find these details can be quite inaccurate and are almost entirely unregulated; Claimed water resistance, shockproofing, anti-magnetic properties, etc.
Watch Testing
Many watch manufacturers may bend the truth a little to suit the latest market trends or cut corners, and will often get away with it because let's face it, most customers will rarely test the claimed capabilities of the watch. That is, unless your customer is the United States Government, and you must comply with the Nuclear Regulatory Commission standards! The relatively modest spec sheets on Marathon’s website pale to insignificance when you consider the additional trials and tribulations these military-specified watches must withstand. Fortunately, 4th Generation Canadian family-owned Marathon watches has been supplying no-nonsense timepieces to Allied Forces since 1941, and take these challenges in their stride.
Printed on the back of each Marathon watch are several obscure ID numbers and codes. Curious, I plugged these numbers into Google, and a whole heap of very serious and official US government documents popped up. After a little perseverance reading the boring introductory pages, I started to get into the good stuff and a bunch of very practical, but rather humourous test scenarios were revealed. Feel free to stick the Military Performance Specification Number (MIL-PRF-46374G) into your search bar and check out the US Nuclear Regulation Commission specs for yourself, but below are some of the more choice experiments these Marathon watches have passed:
“Human Perspiration Resistance”: The watch case and strap should be resistant to human perspiration. To test this, the watch should be immersed in a saturated sodium chloride solution containing 5% lactic acid at 91C, removed and allowed to dry for 1 hour, followed by 20 hours in a solution of 50% glacial acetic acid (clinical vinegar). The watch should show no adverse signs of degradation. [Am I the only one disappointed that they didn’t use actual human perspiration for this!?]
“Dark Viewing”: The watch must be kept in total darkness for 8 hours, and the dial should be readable at a distance no closer than 30.5cm, by an observer, having normal or corrected 20/20 vision. That observer should also have been kept in total darkness for 20 minutes prior to conducting the test to allow their eyesight to adapt to the darkness. [I've heard of being kept in the dark, but this takes it to a whole new level. This "Dark Viewing" requirement, turns out to be quite a challenge for a mechanical watch and led Marathon to utilize Tritium Gas Tubes for their hands and hour markers. Tritium is a radioactive isotope and is used in nuclear fission and thermonuclear weapons. But don’t worry, this thing isn’t going into melt-down if you ding it on a door frame, and you won’t grow an extra finger from the radiation. Tritium emits Beta Radiation - barely strong enough to leave the watch, and certainly not powerful enough to penetrate the outer layer of dead skin covering your body - although, it's recommended not to consume it. These low-energy electron particles collide with phosphor powder coating the inside of sealed tubes, emitting light as the radiation is absorbed by the phosphor. This type of light generation requires no external power source, you don’t need to charge it in the sun or with a UV light. It just glows and glows day or night. Though relatively harmless, Tritium is a radioactive substance and as such, Marathon is required to print a Radioactive symbol on the dial and confirm the maximum radioactivity of 25 Millicuries on the case back.
“Shock testing”: We often see Manufacturers claiming their watches are "shockproof". Movement manufacturers have various different ways to test how shock-resistant their products are. The US military requires the watch to be unaffected by a “drop from a height of 50cm onto vinyl tile 3mm thick affixed to a concrete block.” Perhaps it’s just me, but I really enjoy the absurdity of having to specify the thickness of the vinyl tile attached to a concrete block, which you’re going to drop the watch onto to test its shockproof capabilities. I wonder if they thought 2mm was taking it too far..
Others: There are of course other tests including water resistance under pressurized distilled water, scratch-resistant crystal requirements, and how much pressure the spring bars should be able to withstand without failing (67 Newtons/15lbs)
Movements
The 34mm model houses the ubiquitous Seiko NH35A; a reliable automatic winding movement, which is cheap, maintainable (though likely cheaper to replace than repair), and generally gets the job done in hundreds of thousands of similarly priced affordable mechanical watches. Though accuracy is quoted as being between pretty tame at -20 to +40 seconds per day, I found the model tested was approximately +10 seconds a day fast. And if it's good enough for Uncle Sam, it's good enough for me.
The 36mm was a little more of an interesting story, with a hand-wound movement. Some folks prefer winding their watches manually each day as a bit of a routine. I am so used to automatic movements I forgot to wind it the first few days of testing. But I grew to enjoy it and it became a habit. But going back to my point on websites not always being 100% accurate, I found the specs on Marathon's website very confusing.
The main picture for the 36mm GPM-SS shows a large dial image with “17 Jewels” on the face, however, the smaller images showed an “18 Jewels” dial. Looking at the main page text it clearly states the movement is an ETA 2801 with 17 Jewels, but scroll down to the technical specifications and it states it's an ETA 2801 with 18 Jewels - how can the same movement have two different Jewel counts? Clicking into the product manual/tech sheet it states the movement is a completely different movement - a Sellita SW210-1 which truly is 18 jewels. Quite a mess, to be honest, not just a typo, but two completely different movements are being referenced.
Opening the caseback I found an ETA 2801 and it started to become clear what was going on here. I contacted Marathon directly, who confirmed my suspicions – the ETA 2801 was originally being used by Marathon prior to Swatch Group restricting the supply of ETA movements to 3rd party manufacturers. When ETA movements were removed from the shelf and the inventory of ETA movements dried up, Marathon moved to the Sellita caliber SW210-1. It’s not clear when the switch was made but I would imagine by now new orders are likely to be Sellita-based versions. The movement itself is pretty good - slightly more accurate than the NH35A and includes a concentric screw to help accurately regulate the watch - far better than the 'nudge and hope' technique required in the NH35A.
Case Constrution & Dimensions (GPM-SS)
Housing the hand-wound ETA/Sellita movements is the 36mm 316L stainless-steel case. The case construction is a once-piece solution with no separate bezel. The finishing is a very flat ‘parkerized’ coating which is a chemical layer protecting the 316L stainless steel - from acidic human perspiration, among other things!
Where a traditional pressure-fit bezel would have been, the case drops steeply away from the dial and curves out into the main body of the case. Squared-off lugs have a 16mm lug width and a distance of 44mm lug-to-lug. The lugs are pretty beefy for the size of the case, they are drilled to allow easy strap changes. Deceptively, viewed from the side, the lugs appear to drop away from the case, but the undersides are flat and exactly parallel to the caseback.
The lugs do not curve down below the caseback to hug your wrist. It's quite an awkward look. I assume the design is due to the relatively small case size and short lug-to-lug distance, the expectation is that the entire case will sit on the flat part of your wrist, so there is no need to angle the lugs to curve around the sides of your wrist. It is a fair assumption for any wrist at 6.5” and above. Indeed if the lugs were to protrude below the caseback, they might dig into your wrist.
On the reverse is a screw-down caseback with a plethora of official codes engraved into the steel, referencing the various NATO and Governmental specifications it conforms to. Interestingly, there is virtually no crown protection, though the case is asymmetrical. The crown is very plain and does not screw down, however, internal gaskets prevent water ingress. As a result, water resistance seems rather puny at 3atm/30m. But it should be noted that these things are contractually bound and tested to resist water ingress to 30m. Marathon confirmed to me that they are guaranteed to 30m, but should be resistant up to 50m.
Specifications
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34mm General Purpose Mechanical |
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Case Diameter: |
34mm |
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Lug-to-Lug: |
41mm |
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Case Thickness (Incl. Crystal): |
12.7mm |
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Movement: |
Seiko NH35A, automatic |
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Power Reserve: |
41 hours |
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Case: |
Composite Fibreshell |
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Water Resistance: |
3atm/30m |
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RRP: |
$450 |
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36mm GPM Stainless Steel "Officer's Watch" |
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Case Diameter: |
36mm |
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Lug-to-Lug: |
44mm |
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Case Thickness (Incl. Crystal): |
10.8mm |
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Movement: |
Manual wind. ETA 2801-2 17 jewels / Sellita SW210-1 18 jewels |
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Power Reserve: |
42 hours |
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Case: |
316L Stainless Steel |
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Water Resistance: |
3atm/30m* |
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RRP: |
$565 |
Marathon 34mm GPM
The 34mm GPM has even fewer frills than its bigger brother. With a chunky “composite fibreshell” case in black, sage green, or desert tan, this thing looks more like a piece of Lego than a watch. Extending above the plastic-looking case is a central core of metal that holds the sapphire crystal. The plastic surround provides external shock absorption and is shaped into rudimentary lugs where fixed metal lug bars are pressed into the case. These are not removable, so you're stuck with Nato-style straps (if you can find them at 16mm wide).
The very short lug-to-lug distance of 41mm x 34mm case diameter makes the 12.5mm case thickness seem proportionally clumsy. The flimsy-looking 16mm nylon strap doesn’t do it any favors either – it literally feels like you’ve tied a kid’s watch to your wrist with a piece of string. However, it is ballistic nylon and conforms to the Mil-Specs.
Comparing the models side-by-side, the dial apertures of the 34mm and 36mm models are almost identical. Due to the way the stainless steel case frames the 36mm model's dial compared to the almost bezel-less construction of the 34mm model, counterintuitively, the 34mm dial appears larger than the 36mm model. You may also notice that the hand-wound stainless-steel model has a few additional points of interest on the dial:
The 36mm model has sub-second markers at 1/5th of a second, and the 34mm has seconds-only demarcations making it appear more open.
The second hand of the larger model has a small Tritium tube and red tip, making it more visible day or night, whilst the 34mm has a plain painted arrow-shaped seconds hand.
Printed in the lower half of the dial is “17 Jewels” or “18 Jewels” depending on the movement within. The 34mm does not specify the jewel count.
It came as a surprise to me that I actually preferred the plastic case model over the metal, I found the mixture of flowing curved case lines combined with the thick squared-off lugs a little jarring on the Officer's watch. The plastic watch felt a bit more cohesive.
What I liked
Forget your fictional British Spy movie collaborations and thin gimmicky armed forces affiliations. The casebacks on these watches are proof that they comply with, and are used by, the US government, NATO and other international agencies. These engravings are not designed to be an advertisement, they’re there in order to facilitate issuing to military personnel.
On a similar theme, I truly enjoyed how utterly utilitarian these watches are – there is absolutely zero consideration for pomp or ceremony. The lugs are shaped the way they are to prevent failure. The cases do only what they are required to do. One is plastic because plastic is good enough. The watches contain radioactive material because it’s the best solution for the low light requirements specified. The results are brutalist, borderline ugly watches, and I love that. They challenged my understanding of how a watch needs to look in order to perform in a physically demanding environment. After all, the various expectations and scenarios presented by the military are far more scientific than my subjective views on polished bevels.
The Radioactive symbol on the dial is really the only external indication that this is a very serious watch. For all intents and purposes, these things look like something my toddler might wear. But when the Trefoil symbol catches your eye, you immediately know they mean business.
What I didn’t like
Whilst the low light visibility is guaranteed, and highly unusual, it’s not particularly bright – especially if you haven’t sat in the dark for 20 minutes prior to checking the time! It also means that these watches have a limited lifetime. The Half-life of Tritium is just over 12 years. Meaning that in 12 years time, half of the Tritium will have decayed away, in another 12 years, you’ll only have ¼ of the Tritium the watch began with. It will still glow, but far less brilliantly than it did originally. With the disappointingly low brightness to begin with, I’m not sure ½ or ¼ of the brilliance is going to cut it, and so these watches have a 5-10 year shelf life.
The very narrow lug width of 16mm will make finding good straps quite difficult. The straps that come with these watches are painfully utilitarian, with next to no charm about them. You definitely feel like you're wearing a tool, rather than something that brings you joy.
The case shape on the Officer’s Mechanical combines a mixture of very unusual flowing curves from the crystal into the main case, but the lugs are extremely angular. In side-profile, you can see that they begin to angle down, but then level off to horizontal at their extremes. The overall effect is quite awkward and makes the lugs appear like they are bent – it’s a trick of the eye, but they almost appear to be pointing upwards, away from your wrist. From the top, they have a very square profile. I can cope with the utter blockiness of the 34mm General Purpose plastic case, because its case shape is 100% utilitarian. What I find strange with the Officer’s Watch is the mixture of flowing curves, abruptly interrupted by these weird blocky lugs. I imagine both the curves and the blocky lugs were developed with pure functionality in mind, I can’t help but think there might have been a more cohesive design which was either all curves with (C-case style lugs), or entirely angular like 36mm’s smaller counterpart.
Alternatives
Objectively, I think a digital G-Shock is probably tougher and has more functionality than these primitive timepieces (a G-Shock Square would laugh at a drop of 50cms - vinyl or no vinyl). Indeed several G-Shocks have NATO Stock Numbers, meaning NATO have approved them for use in military applications just like the Marathons:
DW-9052-1V - Very popular with multiple military and emergency services
DW-6600-1V - Allegedly the choice of US Navy Seals
DW-6900-1V - Similar to the 6600 with triple graph display
DW-5600E-1V “Square” – The classic, beefed-up digital sidekick.
I guess the Marathons are a little more subtle than the G-Shocks, but still, I think the bombproof Casio’s are very hard to beat if utter utility is your top priority.
Marathon also offers a slightly larger and more traditionally cased (though still heavily utilitarian) watch in the 41mm NAV series. In steel or plastic asymmetric cases and with a dive bezel, 20mm lug-width and 60m of water resistance, this scratches the same blunt military tool watch-itch as the 34mm GPM, but in a much more conventional and aesthetically pleasing design.
Conclusion
These two GPMs are objectively challenging watches to love. They’re weird-looking and awkwardly shaped. But If you’re willing to forgive the odd looks and child-like straps, beneath the surface are immensely capable, reliable timepieces developed with toughness and survival in mind.
They are the very definition of an “if you know, you know” timepiece – you’d have to be a true watch enthusiast to opt for a 34mm, plastic watch that emits beta-radiation and looks like you stole it from a 4 year old. If you see someone wearing a Marathon on the street, they're either a true watch geek, or they're a service member and either way, they deserve some respect.